1. Field of the Invention
The present invention relates to universal optical fiber connectors and their basic plugs, wherein the optical fiber connectors have some common elements for their connector-functions to permit an installation of optical fiber into one of the different type connectors for establishing their connector to connector connection more easily and to facilitate a tuning operation with positioning key maintaining the same direction between eccentricity of the fiber core and the key.
For the sake of clarity, in general, the technical term xe2x80x9coptical fiber connectorsxe2x80x9d means all of elements where each of them is terminated on an end portion of an optical fiber. Conceptually, the optical fiber connector may be of any shape, such as a plug with a tip formed as a male member, an adapter with a tip formed as a female member, a combination thereof, or the like.
2. Description of Related Art
Heretofore, an optical fiber connector has the configuration in which a ferrule is coupled to a plug flame after fixing an optical fiber into the center of the ferrule to establish a connection between different optical fibers in opposite directions.
A FC-type plug as an example of such conventional optical fiber connector is depicted in FIG. 24. As shown in the figure, the FC-type plug comprises a ferrule 101, a frame 102, and a tightening member 103, with an integrated configuration of coaxially arranging these elements around a bare optical fiber 99 as the center thereof. Furthermore, there is a key ring 104 oriented along a direction of a displacement of the center of the bare optical fiber 99 fixed in the ferrule 101.
For coupling the plugs 100 together, it is necessary to provide an adapter 201 for connecting plugs to its ends, respectively. The adapter 201 is comprised of a flange portion 202 and a cylindrical portion 203 in a one-piece design. An outer peripheral surface of the cylindrical portion 203 has a male screw thread 204 and a depressed portion 205. Also, a mating slot 206 is concentrically formed in the center of the cylindrical portion 203. In an inner side of the mating slot 206, there is a separate sleeve 207 on which the ferrule 101 of the plug 100 is fit and attached in a removable manner.
For coupling the plug 100 with the adapter 201, a positioning key 104a is engaged into the depressed portion 205 in addition to fitting the ferrule 101 of the plug 100 into the separate sleeve 207 of the adapter 201 to adjust their positions so as to be in their right places in a circumferential direction. Then a female thread 105a of a coupling nut 105 is screwed to a male screw thread 204, so that the plug 100 is coupled to the adapter 201 tightly and thus it prevents them from becoming detached.
Up to the present, optical fiber connectors of the FC SC, ST type and so on with various connection forms have been commercially used. In this case, the different type optical fiber connectors are grouped together so as to put them to proper use. Under certain circumstances such as the changing of a system configuration, the need for the mutual connection between the different types of optical fiber connectors comes about and thus a converting adopter is required. Therefore, there are several problems including that many different type of converting adapters should be prepared so as to be used in the mutual connection and a quality of signal to be transmitted is decreased as an optical loss in optical transmission path is increased.
Conventionally, furthermore, it is very difficult to detach the key ring when it should be shifted in the right place to adjust eccentricity of the fiber core after the completion of the connector assembly. Depending on the connector type, moreover, the position of the key ring cannot be re-adjusted.
There may be cases where the optical fiber connector is fitted to an end portion of an optical fiber cable or an optical fiber code in installing the necessary wiring in building, mechanical system, or the like. In this case, optical fiber connectors of the FC, SC, ST type, and so on with various connection forms should be selected and combined to proper use depending on their applications.
Under certain circumstances, such as the changing of a system configuration, the need for the mutual connection between the different types of optical fiber connectors comes about and thus a converting adapter required. Therefore, there are several problems including that many different types of converting adapters should be prepared so as to be used in the mutual connection and a quality of signal to be transmitted is decreased as an optical loss in optical transmission path is increased.
In general, an adapter to be provided as a coupling portion of the optical fiber connector has two end portions, one for fixing on a fixing member such as a panel and the other for receiving a plug to be fixed to an optical fiber cable or the like.
There may be cases where a ferrule""s tip of the plug fixed through the adapter requires cleaning for preventing a loss in the optical transmission path. However, there is a problem that it is very difficult to clean the ferrule""s tip of the plug in a state of being coupled with the adapter.
To solve those problems laid open, Japanese Patent Application No. 122570/1996 discloses a tightening mechanism of plug that allows removal of a an adapter from its fixing member.
According to the above document, there is a problem that the method is costly performed because it requires an intricate structure for laterally fixing a standard type plug on a fixing member such as a panel in a special shape.
For using the optical fiber connector in installing the necessary wiring in a building or a mechanical system, as described above, the optical fiber connector should have an excellent strength against bending stress.
For use in various environments, the optical fiber connector should long term stability.
Therefore, a first object of the present invention is to provide a basic plug to solve the above problems in the conventional related art and to easily establish connection with an optical fiber without depending on the type of connector to cope with much more sophisticated devices.
A second object of the present invention is to provide a universal optical fiber connector to solve the above problems in the conventional related art and to easily establish connection with an optical fiber without depending on the type of connector to cope with much more sophisticated devices.
A third object of the present invention is to provide a jack-housing to solve the above problems in the conventional related art and to easily establish connection with an optical fiber without depending on the type of connector to cope with much more sophisticated devices.
A fourth object of the present invention is to provide a universal optical fiber connector that enables the user to clean a ferrule""s head in spite of being fixed on a panel or the like.
A fifth object of the present invention is to provide a universal optical fiber connector that enables its end portion connecting with an optical fiber or the like to generate an excellent strength against bending stress.
A sixth object of the present invention is to provide a ferrule-holding member and a universal connector to be manufactured at low cost with the properties of rust free and good environmental stability.
In the first aspect of the present invention, a basic plug for connecting separate optical fibers together through a housing member comprises:
a ferrule having at least one common dimensional structure for securing an optical fiber;
a spring element being held so as to exert force against said ferrule in an axial direction; and
a cylindrical tube having a function of securing an optical fiber cable in which said optical fiber is embedded and a function of holding said spring element by sandwiching said spring element between said cylindrical tube and said ferrule, wherein
said basic plug has a shape that enables to engage said housing member and to connect said optical fiber to another optical fiber through said housing.
Here, the basic plug may further comprise an engaging member that includes:
a mating portion having a flange on at least a part of a periphery thereof, in which the rear end portion of said ferrule is fitted;
a long-sized cylinder portion coaxially arranged on said rear end portion of said ferrule, on which said spring element is held; and
an engaging portion to be engaged to said cylindrical tube formed on the rear end portion of said long-sized cylinder portion, wherein
said spring is held between said flange of said mating portion and said cylindrical tube by engaging said engaging portion to said cylindrical tube in addition to hold said engaging portion on a periphery of said continuous cylinder portion.
The engaging portion may be continuously formed on said long-sized cylinder portion and is provided as an engaging protrusion that protrudes outward and is inwardly deformable in a radius direction, and said engaging protrusion and said long-sized cylinder portion are able to insert in said cylindrical tube where an engaging hole in which said engaging protrusion is able to engage.
The insert-restricting portion for restricting an amount of inserting said long-sized cylinder portion to said cylindrical tube may be mounted on an outer peripheral surface of said long-sized cylinder portion.
The insert-restricting portion may be a protrusion or short-sized cylindrical tube having an outside shape thereof which is a slightly larger than an inner diameter of said cylindrical tube.
In the second aspect of the present invention a universal optical fiber connector, comprises:
a basic plug of the first aspect of the present invention, and
a housing member to be fitted on said basic plug.
Here, the housing member may incorporate a sleeve to be fitted on said ferrule, and also said housing member has an engaging portion on its tip portion on a side thereof opposite to a side of said basic plug, where said engaging portion conforms to various kinds of connector forms.
The plug housing may comprise: a key member for an alignment in a diagonal direction around an axis of said ferrule; and a plurality of engaging holes, and
said cylindrical tube of said basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said plug housing.
The plug housing may connect to a plug that conforms to various kinds of connector forms through an adapter that conforms to various kinds of connector forms to allow an optical connection between an optical fiber fixed in said ferrule and an optical fiber fixed in a ferrule in said plug.
The housing member may be an adapter housing having an engaging portion on its tip portion on a side thereof opposite to a side of said basic plug, and
said engaging portion is for engaging to another basic plug that conforms to various kinds of connector forms, wherein
at a time of engaging another basic plug in said engaging portion of said adapter housing, a ferrule of another basic plug is fitted into said sleeve to allow an optical connection between an optical fiber in said ferrule and said optical fiber in said ferrule of said basic plug.
The adapter housing may comprise: a key member for an alignment in a diagonal direction around an axis of said ferrule; and a plurality of engaging holes, and
said cylindrical tube of said basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said adapter housing.
On a side of said tip portion of said adapter housing, there may be a key member for an alignment in a diagonal direction around an axis of said ferrule of another basic plug; and a plurality of engaging holes, and
a cylindrical tube of another basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said adapter housing.
The adapter housing may be able to engage to a plurality of said basic plugs, and
a tip portion of said adapter housing has a plurality of engaging portion to be engaged to another basic plug.
The housing member may be a jack housing having an engaging portion on its tip portion on a side thereof opposite to a side of said basic plug, and
said engaging portion is for engaging to a plug that conforms to various kinds of connector forms, where
at a time of engaging another basic plug in said engaging portion of said jack housing, a ferrule of another basic plug is fitted into said sleeve to allow an optical connection between an optical fiber in said ferrule and said optical fiber in said ferrule of said basic plug.
The jack housing may comprise: a key member for an alignment in a diagonal direction around an axis of said ferrule; and a plurality of engaging holes, and
said cylindrical tube of said basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said jack housing.
The plug may be a plug that conforms to an optical fiber connector in a type of one selected from a group of FC, SC, and ST.
In the third aspect of the present invention, a jack housing for a universal optical fiber connector to be used for fitting to a basic plug of the first aspect of the present invention to allow an connection between said basic plug and a plug that conforms to various kinds of connector forms, comprises:
an sleeve integrated therein to be fitted to said ferrule;
an engaging portion formed on one side thereof to be engaged to said basic plug; and
an engaging portion formed on the other side thereof to be engaged to said plug that conforms to various kinds of connector forms, wherein
a ferrule of said plug is fitted in said sleeve when said plug is engaged to said engaging portion, allowing an optical connection between an optical fiber of said ferrule and said optical fiber in said ferrule of said basic plug.
Here, jack housing may comprise: a key member for an alignment in a diagonal direction around an axis of said ferrule; and a plurality of engaging holes, and
said cylindrical tube of said basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said jack housing.
The plug may be a plug that conforms to an optical fiber connector in a type of one selected from a group of FC, SC, and ST.
The housing member may have one end portion provided as a plug housing that conforms to various kinds of connector forms, wherein
a flange portion is formed on at least one part of an outer peripheral portion of said plug housing, for fixing said plug housing on a fixing member.
The plug housing may comprise: a key member for an alignment in a diagonal direction around an axis of said ferrule; and a plurality of engaging holes, and
said cylindrical tube of said basic plug has at least one elastic engaging piece, wherein
said elastic engaging piece is able to engage in a predetermined engaging hole selected from said plurality of said engaging holes at a time of inserting said cylindrical tube into said plug housing.
The plug housing may connect to a plug that conforms to various kinds of connector forms through an adapter that conforms to various kinds of connector forms to allow an optical connection between an optical fiber fixed in said ferrule and an optical fiber fixed in a ferrule in said plug.
The flange portion of said plug housing may have a hole for tightening with a thread member.
In the fourth aspect of the present invention, a universal optical fiber connector, comprises:
a basic plug as claimed in claim 1; an engaging ring for connecting an optical code tensile strength body to an outer peripheral portion of said basic plug; a plug housing for covering said ferrule and said basic plug; a hood having a securing hole for securing an optical code, where said hood fits on an outer peripheral portion of said plug housing and covers a connected portion of said optical code tensile strength body, said optical fiber connector further comprising:
a reinforcing pipe having one end portion to be fitted on an outside of said plug housing and the other end portion surrounding said engaging ring.
Here, the reinforcing pipe may be:placed on an inner peripheral portion of said hood.
In the fifth aspect of the present invention, a universal optical fiber connector, comprises:
a ferrule having at least one common dimensional structure for securing an optical fiber;
a forcing element made of rubber or elastomer, being held so as to exert force against said ferrule in an axial direction; and
a securing member for securing said forcing member for sandwiching said forcing element between said securing member and said ferrule; and
a connecting member for incorporating said securing member and for connecting to a plug or adapter of various kinds of connector forms.
Here, the connecting member may be a plug housing which is able to connect to an adapter that conforms to various kinds of connector forms.
The connecting member may be an adapter housing which is able to connect to an adapter that conforms to various kinds of connector forms.
In the sixth aspect of the present invention, a ferrule holding member comprises:
a ferrule having at least one common dimensional structure for securing an optical fiber;
a forcing element made of rubber or elastomer, being held so as to exert force against said ferrule in an axial direction; and
a securing member for securing said forcing member for sandwiching said forcing element between said securing member and said ferrule.
Here, securing member may be a cylindrical tube having a function of securing an optical fiber cable in which said optical fiber is integrated.
The forcing member may be shaped so as to hold a plurality of ferrules in parallel.